Efforts in developing new drugs for the treatment of the cognitive impairment associated with Alzheimer's disease are now hindered by the lack of access of many investigators to animal testing facilities. The present paucity of any compounds which can uniformly slow or reverse the progression of Alzheimer's disease or ameliorate the symptoms requires that every effort be made to facilitate the development and testing of new compounds. However, there are still gaps in the overall effort to facilitate the development and testing of new compounds. Specifically, resources are needed by investigators who are developing new compounds so that the potential adverse toxicological activity of the compounds can be evaluated before they can be taken into clinical trials. The purpose of this contract is to evaluate acute and chronic toxicity in rodents and dogs of drugs which are proposed to have potential use in the treatment of Alzheimer's disease. The data generated from those studies will be used as part of the filing of an Investigational New Drug (IND) Application to the Food and Drug Administration (FDA) in order to receive approval to use the drugs in humans. Thus, this project will provide access to resources for the toxicological screening needed in order to request an IND designation from the FDA and will expand drug development efforts for Alzheimer's disease to a larger and more diverse group of investigators.